In a liquid crystal display device, due to the fact that the liquid crystal of a liquid crystal display panel itself has no function of light-emitting, it is necessary to provide a light source, such as backlight module, for the liquid crystal display panel to realize a display function. A backlight module can be divided into: an edge-lit backlight module and a direct-lit backlight module.
With continuing extension of the application fields of liquid crystal display devices, especially the applications of large-sized liquid crystal display devices, further requirements are put forward about the light-emitting brightness of a backlight module of a liquid crystal display device; for this reason, it is necessary to use a plurality of light-emitting elements to increase the light-emitting brightness of a backlight module, and a direct-lit backlight module meets such a demand.
A direct-lit backlight module comprises: a back cover; a plurality of light-emitting elements arranged side by side; a backlight lamp guide, supported and fixed on the back cover for securely positioning the light-emitting elements; and a reflecting plate provided on the back cover and used for reflecting the light emitted from the light-emitting elements (also may be reflectors or films provided by coating or adhesion on one face of the back cover that contacts with the backlight lamp guide). The light-emitting elements are fixed by a lamp clamping portion 2 of the backlight lamp guide of the liquid crystal display device. As shown in FIG. 1, the backlight lamp guide of the liquid crystal display device is connected to the back cover (in a backlight source, there may be a plurality of sets of backlight lamp guides of a liquid crystal display device, although only one set is shown in the figure). The backlight lamp guide comprises: a fixed base 3′, a lamp positioning structure, and a supporter 1′ for supporting optical films such as a diffusion plate. The lamp positioning structure is provided on two sides of the fixed base 3′; the supporter 1′ is provided at an intermediate portion on an upper surface of the fixed base 3′. The lamp positioning structure comprises: a lamp clamping portion 2′ used for fixing a lamp (such as cold cathode fluorescent tube), and a snap-fit structure 4′ used for fixing the backlight lamp guide of the liquid crystal display device on the back cover. The lamp clamping portion 2′ and the snap-fit structure 4′ are integrally molded; the bottoms of the supporter 1′ and of the lamp clamping portion 2′ are connected by the fixed base 3′. The snap-fit structure 4 passes through a hole on the back cover, the snap-hooks of the snap-fit structure 4 retracts while passing through the hole and expands after passing through the hole, thereby clamping the back cover between the lower surface of the lamp clamping portion 2 and the upper surface of the snap-fit structure 4, so as to position the backlight lamp guide with respect to the back cover.